Cod sursa(job #1978925)

Utilizator LittleWhoFeraru Mihail LittleWho Data 9 mai 2017 08:38:27
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.59 kb
#include <fstream>
#include <iostream>

using namespace std;

#define UPDATE 1
#define QUERY 0
#define MAX_N 100001

int range_tree[4 * MAX_N + 66];

int pos, val;
int target_l, target_r;
void update(int node, int l, int r)
{
    //cout << node << " " << l << " " << r << " " << pos << " " << val << endl;
    if (l == r) {
        //cout << "oke!" << endl;
        range_tree[node] = val;
		return ;
	}

    int m = (l + r) / 2;
    if (pos <= m) {
        update(2 * node + 1, l, m);
	} else {
		update(2 * node + 2, m + 1, r);
	}
	range_tree[node] = max(range_tree[2 * node + 1], range_tree[2 * node + 2]);
}

int max_q;
void query(int node, int l, int r)
{
	//cout << l << " " << r << " " << target_l << " " << target_r << endl;
    if (target_l <= l && target_r >= r) {
		if (range_tree[node] > max_q) max_q = range_tree[node];
		return ;
    }

    int m = (l + r) / 2;
	if (target_l <= m) {
		query(2 * node + 1, l, m);
	}
	if (target_r > m) {
		query(2 * node + 2, m + 1, r);
	}
}

int main() {
	freopen("arbint.in", "r", stdin);
	freopen("arbint.out", "w", stdout);

	int n, m;
	cin >> n >> m;

    for (int i = 0, x; i < n; i++) {
        cin >> x;
        pos = i;
        val = x;
        update(0, 0, n - 1);
    }

	for (int i = 0; i < m; i++) {
		int op, a, b;
		cin >> op >> a >> b;
		if (op == QUERY) {
            target_l = a - 1;
            target_r = b - 1;
            max_q = -1;
			query(0, 0, n - 1);
			cout << max_q << "\n";
		} else {
		    pos = a - 1;
		    val = b;
			update(0, 0, n - 1);
		}
	}

	return 0;
}